The original fix contained a known data integrity issue, as documented in:

http://support.microsoft.com/kb/920958

When MS06-049 is installed on an NTFS formatted drive and NTFS compression is enabled for individual folders, data corruption may occur.

On September 26, 2006, Microsoft reissued MS06-049 to correct system integrity issues with the previous version of the patch. Affected users should reapply the update [which uses the same URL as the original update].